Unitary multiple electrode sensor

Abstract

A unitary multiple electrode sensor for detecting analytes in blood or blood component samples and devices for using them. The unitary multiple electrode sensor includes a sensor support member and at least one electrode array being deposited on the sensor support member, the electrode array having sensor-activating chemical(s) attached to an embodiment thereof. A test sample is applied to the electrode array to begin the test; and a sensor apparatus measures the test reaction which is occurring on the electrode array.

I claim: 
     
       1. A method for performing an immunoassay of an analyte in a blood or a blood component test sample on a unitary electrochemical sensor, the method comprising: (a) applying a test sample onto a unitary electrochemical sensor, said sensor comprising: (i) a sensor support member including an electrically non-conductive surface; and   (ii) a plurality of wells deposited on the support member, wherein within each well is deposited an electrode array, the array defining an area on the support member for applying a test sample, the array consisting of a working electrode, a counter electrode and a reference electrode; and wherein the electrodes of the array are spaced from one another horizontally and vertically in said well, and wherein sensor activating chemicals are located on or attached to the working electrode of the array, the sensor activating chemicals comprising an electron transfer mediator, a first conjugate including a specific binding partner for the analyte to be measured, and a second conjugate including a known amount of the said analyte attached to an oxidizing catalyst or oxidizing substrate; and wherein the second conjugate is located on or attached to the working electrode of said array following the application of the test sample;     (b) applying an electron source onto the array on which said test sample was applied;   (c) applying a preselected potential between the working electrode and the counter electrode of the array;   (d) measuring the current between the working electrode and the counter electrode of the array; and   (e) determining the amount of the analyte in the test sample from the measurement of the current in step (d) relative to the preselected potential of step (c).   
     
     
       2. The method of claim 1, wherein said first conjugate and said second conjugate are attached to distinct magnetic particles. 
     
     
       3. The method of claim 2, wherein said magnetic particles are drawn to a magnet during the performance of said immunoassay; and wherein said magnet is located adjacent to the working electrode of the array. 
     
     
       4. The method of claim 3 wherein said magnet is a component of an apparatus, said apparatus being adapted to receive the unitary electrochemical sensor. 
     
     
       5. The method of claim 1, wherein said electron source is glucose; and wherein said oxidizing catalyst is glucose oxidase. 
     
     
       6. The method of claim 1, wherein said electron transfer mediator is ferrocene. 
     
     
       7. The method of claim 1, wherein said electron source is an immunoglobulin; and wherein said oxidizing catalyst is an immunoglobulin-glucose oxidase conjugate of the same immunoglobulin as said electron source. 
     
     
       8. The method of claim 1, wherein said analyte is an antibody or an antigen.